package com.chanzany.facade;

//立体声
public class Stereo {
    private static final Stereo instance = new Stereo();
    public static Stereo getInstance(){return instance;}
    public void on(){
        System.out.println("Stereo on");
    }
    public void off(){
        System.out.println("Stereo off");
    }
    public void up(){
        System.out.println("Stereo up");
    }
    public void down(){
        System.out.println("Stereo down");
    }
}
